*{margin:0;padding: 0}
    .nav{
        line-height: 90px;
        text-align: center;
        height: 90px;
        background: #fff;
        box-shadow: 0 0 3px 4px rgba(0, 0, 0, .15);
        font-size: 28px;
        font-weight: bold;
        }
    div{
        width: 800px;
        margin: 0 auto;
    }
    h4{
        line-height: 50px;
    } 
    h4:hover{
        opacity: .5;
    }  
    img{
        width: 800px;  
    }
    .container{
        width:800px;
        margin-left: auto;
        margin-right: auto;
    }
    .content:hover{
        color:coral;
        line-height: 30px;
    }
    li{
        cursor:pointer;
        padding: 5px;
    }
    p:hover{
        color:#ff6633
    }
    li:hover{
        color: #ff6633;
    }
    li{
        padding:5px;
    }
    dl{
        margin-top:15px;
    }
    dl:hover{
        color:#ff6633;
    }
    dt{
        margin:5px;
    }